Upper Heating Value

The amount of heat produced by the complete combustion of a unit quantity of fuel. The upper heating value is obtained when all products of the combustion are cooled down to the temperature before the combustion and the water vapor formed during combustion is condensed.

Also known as Gross Heating Value; High Heating Value.

Common units used for heating value are:

1 Btu/lb = 2326.1 J/kg = 0.55556 kcal/kg

1 J/kg = 0.00043 Btu/lb = 2.39 × 10^-4  kcal/kg

1 kcal/kg = 1.80 Btu/lb = 4187 J/kg